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Adaptive beamformer

About: Adaptive beamformer is a research topic. Over the lifetime, 4934 publications have been published within this topic receiving 93100 citations.


Papers
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Patent
27 Apr 2007
TL;DR: In this article, a method and apparatus for imparting coverage gain to cell-edge or cusp mobile subscribers without resort to diluted frequency reuse factors is disclosed, which may be applicable to fixed multibeam systems as well as individual steered beam and spatial null generation antenna systems.
Abstract: A method and apparatus of imparting coverage gain to cell-edge or cusp mobile subscribers without resort to diluted frequency reuse factors is disclosed. Each base station adopts a priori a beam illumination sequence designed to minimize or obviate the likelihood of beam clashes in a narrow beam adaptive beamforming system. Such sequences may be optimized to impact primarily cell-edge subscribers or subscribers within cusp areas of adjoining beams or sectors. The inventive protocols may be applicable to fixed multibeam systems as well as individual steered beam and spatial null generation antenna systems.

20 citations

Proceedings ArticleDOI
01 Nov 2008
TL;DR: An adaptive beamforming in time modulated antenna arrays based on a hybrid analog-digital structure is proposed and can be realized in the first positive sideband by only controlling the switch-on time sequences of each element without any analog multiplier used in the beamforming structure.
Abstract: In this paper, an adaptive beamforming in time modulated antenna arrays based on a hybrid analog-digital structure is proposed. The adaptive beamforming can be realized in the first positive sideband by only controlling the switch-on time sequences of each element without any analog multiplier used in the beamforming structure. Some simulation results are carried out to examine the performance of this beamforming system.

20 citations

Book
30 Jun 2008
TL;DR: This book presents a comparison comparison between Statistical-Based and Direct Data Domain Least Squares Space-Time Adaptive Processing Algorithms and a Look at the Concept of Channel Capacity from a Maxwellian Viewpoint.
Abstract: Preface. Acknowledgments. Chapter 1. What is an Antenna and How Does it Work? Chapter 2. Fundamentals of Antenna Theory in the Frequency Domain. Chapter 3. Fundamentals of an Antenna in the Time Domain. Chapter 4. A Look at the Concept of Channel Capacity from a Maxwellian Viewpoint. Chapter 5. Multiple-Input-Multiple-Output (MIMO) Antenna Systems. Chapter 6. Use of the Output Energy Filter in Multiantenna Systems for Adaptive Estimation. Chapter 7. Minimum Norm Property for the Sum of the Adaptive Weights in Adaptive or in Space-Time Processing. Chapter 8. Using Real Weights in Adaptive and Space-Time Processing. Chapter 9. Phase-Only Adaptive and Space-Time Processing. Chapter 10. Simultaneous Multiple Adaptive Beamforming. Chapter 11. Performance Comparison Between Statistical-Based and Direct Data Domain Least Squares Space-Time Adaptive Processing Algorithms. Chapter 12. Approximate Compensation for Mutual Coupling Using the In Situ Antenna Element Patterns. Chapter 13. Signal Enhancement Through Polarization Adaptivity on Transmit in a Near-Field MIMO Environment. Chapter 14. Direction of Arrival Estimation by Exploiting Unitary Transform in the Matrix Pencil Method and its Comparison with ESPRIT. Chapter 15. DOA Estimation Using Electrically Small Matched Dipole Antennas and the Associated Cramer-Rao Bound. Chapter 16. Non-Conventional Least Squares Optimization for DOA Estimation Using Arbitrary-Shaped Antenna Arrays. Chapter 17. Broadband Direction of Arrival Estimations Using the Matrix Pencil Method. Chapter 18. Adaptive Processing of Broadband Signals. Chapter 19. Effect of Random Antenna Position Errors on A Direct Data Domain Least Squares Approach for Space-Time Adaptive Processing. Index.

20 citations

Journal ArticleDOI
TL;DR: By introducing vector RF multipliers in the proposed frontend, the amplitude and phase of RF signals can be simultaneously controlled by the real and imaginary parts of complex numbers, such that beamforming algorithms derived in complex domain can be directly applied without any form of transformation.
Abstract: The state-of-the-art phased array-based digital beamforming systems suffer from disadvantages of high power consumption, high cost, and system complexity due to the massive use of transmitter/receiver (T/R) modules and high-speed digital and digital–analog mixed devices. In this paper, we point out that by proposing a new concept “complex domain” radio frequency (RF) frontend, the relatively slowly changed waveform delay information required to accomplish adaptive beamforming can be separated from wideband RF signals, based on which a self-contained beamforming system can be implemented with a low-speed baseband. By introducing vector RF multipliers in the proposed frontend, the amplitude and phase of RF signals can be simultaneously controlled by the real and imaginary parts of complex numbers, such that beamforming algorithms derived in complex domain can be directly applied without any form of transformation. By doing so, the massive use of conventional T/R modules and high-speed baseband devices can be avoided. Theoretical analysis and experimental demonstration based on commercial components have validated the proposed approach. Our method is able to significantly simplify the realization and decrease the cost of wideband digital beamforming systems, and can be widely used in low cost, power efficient beamforming applications.

20 citations

Journal ArticleDOI
Osamu Hoshuyama1, Akihiko Sugiyama1
TL;DR: In this paper, a robust generalized sidelobe cancellation structure for adaptive microphone arrays is proposed, which can pick up a target signal with little distortion when the error in the sight direction from the target direction is large.
Abstract: A new robust generalized sidelobe canceller structure suited to adaptive microphone arrays is proposed. In the proposed structure, the blocking matrix incorporates leaky adaptive filters whose input signals are the output of the fixed beamformer. The leaky adaptive filters alleviate the influence of phase error, which results in the robustness. Undesirable target-signal cancellation is avoided in the presence of array imperfections such as target-direction error and microphone-position error. The proposed structure can pick up a target signal with little distortion when the error in the sight direction from the target direction is large. It can be implemented with a small number of microphones. Simulations demonstrate that the proposed structure, designed to allow 20° directional error, reduces interference by more than 18 dB. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 3, 80(8): 56–65, 1997

20 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202371
2022168
2021133
2020154
2019198
2018154